4 ms·
"If GML was an infant, SGML is the bright youngster who far exceeds expectations and made its parents too proud, but XML is the drug-addicted gang member
by biot 12y ago
"If GML was an infant, SGML is the bright youngster who far
exceeds expectations and made its parents too proud, but
XML is the drug-addicted gang member who had committed his
first murder before he had sex, which was rape." -- Erik Naggum
GML is from the late 1960s and is, arguably, easier to read. SGML from the 1980s expanded upon this. XML is essentially just an offshoot of SGML and much less readable than SGML is. For example, here is a valid SGML document:
<anthology>
<poem>
<title>The SICK ROSE
<stanza>
<line>O Rose thou art sick.
<line>The invisible worm,
<line>That flies in the night
<line>In the howling storm:
<stanza>
<line>Has found out thy bed
<line>Of crimson joy:
<line>And his dark secret love
<line>Does thy life destroy.
<poem>
<!-- more poems go here -->
</anthology>
Aside from XML's lineage, there is no shortage of markup languages available with varying levels of readability.
- Touche 12y agoI'm confused, why does anthology have a closing tag but the other elements do not?
- __david__ 12y agoThe same reason <ul> has a closing tag but <li> does not: HTML is SGML where certain tags can be made optional. XML specifically did away with this and made all close tags mandatory (even on contentless tags, which is why xhtml requires you to do <img />).
- Touche 12y agoJust to be clear, are some closing tags optional or are all closing tags optional? If the former, how do you know which?
- justincormack 12y agoYou work it out from the schema - if it is not ambiguous you can omit it.
- Tuna-Fish 12y agoIn this case, the schema probably disallows any other tags inside <line>, which makes </line> superfluous and it can thus be omitted. If <stanza>s are not recursive and poems cannot contain <line>s outside <stanza>s, </stanza> can also be omitted. Etc etc.
- meepmorp 12y agoI think it's funny to see people quoting Erik Naggum, though perhaps that's just because my context for him is largely his rather prolific and fiery output on usenet.
- TeMPOraL 12y agoI don't know much about him except from his essays about time and XML, both of which I think are spot on, despite the fiery language.